Production of unsaturated halides



Patented Jan. 10, 1950 raonncmoncncnsnunnmn George .L .Garlson,. .El -Cerrito, C'alifL, assignori to Shell Development: Company,. Sitnz- Francisc Calif., a corporationznf Delaware No'Drawing: AppllcatiomAugustfieJB-lfi; Seriablalo. 688;41%

5- Claims: (Cl. 280 -1654) This invention .relatesto. a a process of prepar. inge, allyl-typehalides:v More: particularly, the; invention concerns a process .of preparing, in the:

absence: of substantial, polymerization. of; allyl compoundsallylbromide orchloride, and methyl;- substitutediallyl bromide or chloride, which proaessinvolvesreacting an. allyl-type-setherl with: .hy.-- drogen halide: in: ther-- presence of a-v cuprous salt as catalyst.

In accordance with: the present inventionthere:

is provided a process whereby?certaintallyltype; ethers may be; converted .withzthe aid .of.- a par..-

ticular catalysts-to thez corresponding, allyletypei chloride or: bromide. in highyield andwithoub. significant polymerization ofallyl-type. com.-.

pounds. It has, been found. that; solid. cuprous-1 salts, preferably, cuprous. chloride; areefilcient andi highly desirable. catalysts forv the conversion of Q the allyl-type. ethers. to. the allyle-type chlorides? notilsstlianlfi'inor"greater than 8;

2;: of tlie' presentlihventibnare.particularly realized are the.symmetricallunsaturated letliers.containing olfiiiic bonds in the beta,gamma positionsand. containingan..even..number. of (carbon atoms,

Specifically.

' thepresent-Linvention.thusscontemplates the com version oidiallyl ether, -andt'the symmetrical di- (monometliyl' allyl); etliers: di(methally1) ether; dicrotyl .ether"anddii'metliylvinyl carbinyl) ether to. the. corresponding; unsaturatedi chlorides or bromides; i...e., toallylcliloride or bromide, methallyhchloridx or.'bromide, .crotyl'fchloride .or bro-.- mide,..andmethylvinylcarbinyl chloride or bromide;. respectivel-y;. Tli'eaprocess of. the presentisainventionis oflparticular advantage as appliedto the reactiomofiliydrogen chloride or hydrogen. bromide..- with; diallyliether, di(metlia1lyl)- ether, and I dicrotyl" ether.

In: accordance 'witltthe. process or; the" inven-.-.

01' bromides. Thecuprous saltslsuchas cuprous; 2i).:ti0n, the q -L preferably anhyd 'o chloride or cuproushromideareof.Iparticular. ad; vantage inaccordance Withthe. process. ottlie. present invention because through theinuseitds. possibletocarry out the processwith high yields of the allyl-typev chloride or bromide .and'lwitlioutsignificant polymerization of allyletypje compounds.

In the practice of the present invention, the allyl-type ether in the liquid state is reacted with a hydrogen halide selected'from the class;con'- sisting of hydrogen bromide .and .hydrogen chic-'- ride, ata. pressure preferably aboveatmospheric, and at .a temperature .below'theiboiling point of". the ether at the pressure employed inthe presence" of' catalytically active amountsof asolid cuprous: salt, preferably, solid'cuprous halidecontaining the same halogenas'the hydrogen'halide'used'if As the cuprous salt there maybe employedjjor".

be employed: Ithasbeen found-I however; that the use of the-cuprous halide-containingthe samer halogen as the hydrogen-halide=-used=; provides;-

ratedLetlier is .contactediwith a gaseous, substantially, anhydrous hydrogen halide selected from. the... groupvconsisting of hydrogen bromide and; hydrogen .chloride,. inltlie presence of acuprous 25;.salt. present. in.an' amountl suflicient to catalyzethereaction. Catalytictamountsof 'solid cuprous: salt generally... lie vbetweenl-ab'out 0,1 and about. ECO-1% bygwei'gh't offthemnsaturated ether used; Particularly. satisfactory: results. are obtained;

when there are employediamounts of.so1-id. cuprous salt containing thesamelialogen as the hydrogen halides employed;,.in.an amount between about 015% andilabout 2'.0'%1.by weight'of the diallyl ether. Tlie catalyst preferably, isused in the wssolidlstate-i It'may, bezin the form of'lumps: or

oftliereactiom IfifdsiiedQ'the cuprous salt may besupported iin thexeactionzone upon a suitable inert support; su'cli. as; for example, pumice, kieselgulir,.',etc.;

- unsaturated; ether; thehydrogen halide particularly advantageous resultsin? respect? to:v 45c and the cuprous:.salt.l catalyst; may, be brought yield, purity of product; etc., and"*its-"use-; tl'iere=- fore; is preferred: Thus, when all yl-ts' pechlo rides are prepared by reaction of allyl-type-t ether With hydrogen chloride; it" -is=-prefrred to" use cuprous chloride as the 'catalyst. Similarly-when allyl-type bromides are to be prepared by reac tion of allyl-type ethers: withhydrogen bromide, it is preferred to use'-cuprous bromide.- ass the catalyst.

into.- reactive: contactleitlien batcl'iwise or, for examples,by, passing; continuously. the. unsaturated all'yltypfiether; and.'.. hydrogen. halide in thecdesiredlproportionsover .solid cuprous salt at 5Gfsuch airate that .tliezd'sired; contact. time ensues; In. the? case ofilfatch'wise; operation, the symmetrical; zunsaturatedrethercontaining olefinicibondss in the;- b'eta,.,.gammar positions. and. containingeanevemmumben,oficarbonatoms.not

. The allylz-typeethers with'whichthaadvantagese l'e'ssctlian .6: nortgreatem tIianiB'; and. the. desired.

The actual pressure employed depends in part upi on the pressure that is required to introduce the a mixture of liquid ether and gaseous hydrogen halide may be passed, for example, through an elongated reaction chamber of suitable length containing a solid cuprous salt. Alternatively, liquid ether may be passed over a bed of solid cuprous salt positioned in a suitable :chamber and maintained under an atmosphere of the de- '-,-mentioned generally is preferred because of resired hydrogen halide gas. Alternative modes of j" carrying out the process of the'present invention are possible and will be apparent to those skilled in the art. In the case of either continuous cri batchwise operations the olefinic halide reaction product readily may be recovered from the rel acted mixture as by neutralizing any excess hydrogen halide present and separating the organic tional distillation, or byother suitable 'nieans of recovery. Z"

The temperatures and pressureemployed in the process of the present invention are maintained atsuch values during the reaction that the allyltype ether employed remains in the liquid state. The reaction thus carried out at a temperature below the boiling point of the ether at the pressure employed. Preferably the temperature is maintainedwithin the range of about C. to about 90 C., and for most favorableconditions of operation within the range of from about C. to about 40 C. If desired, the temperature may in certain instances be maintained between the boiling points of the unsaturated ether reactant and the olefinic halide product at the pressure employed, thus enabling partial or complete removal of the reaction product as it isformed. Generally, however, it is desired to conduct the reaction in a closed reaction vessel, and hence temperatures below the boiling point of the allyltype ether and corresponding halide at the pressure employed are preferred. The time required for completion of the reaction depends upon the temperature employed, the amount of catalyst present and similar factors; Generally speaking, at about 30 C. and in the presence of about 0.5- 2.0% of catalyst, a reaction time of from about to about 3 hours is satisfactory.

The actual pressure used'in. the process is determined in part by the relative amounts of the unsaturated ether and hydrogen chloride or hydrogen bromide that are tobe contacted. Itis preferable to employ a molar excess of the hydrogen halide over the unsaturated ether. The use of lesser amounts of hydrogen halide, tends to affect adversely the relative conversion of allyltype ether charged to olefinic halide recovered.

Preferably the reactants are employed in a molar.

ratio not less than about 2 moles of the hydrogen halide per mole of the unsaturated ether. For maximum benefits it is desirable to maintain the hydrogen halidezunsaturated ether molar ratio at a value not less than about 4:1.

The reaction preferably is carried outat a pressure above atmospheric obtained by introduction of gaseous hydrogen halide into the reaction chamber, although in certain instances satisfactory results have been obtained at atmospheric pressures. Highly favorable results thus have been obtained using pressures of not less than 30 pounds per square inch (gauge), preferably between about 30 pounds; per square inch (gauge) and about 200 pounds per square inch (gauge).

desired amount of hydrogen halide into the particular reaction vessel or chamber that is used. By providing a sufiicient gaseous volume over the liquid phase of the reaction mixture or a suitable reservoir of hydrogen halide gas, it thus is possible to carry out the process of the present invention at substantially atmospheric pressures. However, the use of elevated pressures as aforesulting favorable effects upon the rate of reaction, extent of reaction, etc. In those instances where the size of the reaction vessel or reaction zone dictates, the pressure may be permitted to rise through the introduction of the gaseous hydrogen chloride to a value sufiiciently high to maintain the desired amount of hydrogen halide within the reaction zone.

.20 components of the reacted mixture as by frac It will be appreciated that by the term hydrogen chloride or hydrogen bromide in the present specification and appended claims, reference is made to anhydrous or substantially anhydrous gaseous hydrogen chloride or hydrogen bromide, respectively, as contrasted to the aque ous acids containing in the order of 45 to 50 weight per cent hydrogen halide. The present process thus is carried out using substantially anhydrous reactants and catalyst i. e., in the substantial absence of added water. Water is formed as one of the products of reaction between the unsaturated ether and the hydrogen halide. Excessive accumulation of such water tends to reduce the yield of olefinic chloride and to promote undesired side reactions. Its removal in continuous operations or in the case of repeated batch-wise operations therefore is desirable, as by replacing the catalyst with fresh anhydrous catalyst or by equivalent means apparent to those skilled in the art. It has been found, however, that the amount of water formed as in one batch operation does not affect adversely the outcome of the process.

The reacted mixture obtained as a result of the present process contains the olefinic halide and any unreacted unsaturated ether as well as residual amounts of hydrogen halide dissolved in the organic materials or in any water that may be present. Small amounts of cuprous salt either as a solid or dissolved in any water present, also may occur. The olefinic halide readily may be separated as by neutralizing any free HCl or HBr, say

with aqueous alkali solution, and fractionally distilling the organic phase of the mixture. Alternative means of separating the olefinic halide maybe used, however, and will be apparent to those skilled in the art.

The process of the present invention is characterized by being adapted to provide under optimum conditions substantially quantitative yields of the olefinic halides based upon the amount of the allyl-ether consumed. The process thus is highly eificient-and is capable of operation with an economy of reactants that renders the process of outstanding value for the commercial production of the olefinic halides herein disclosed.

The following examples will serve to illustrate certain specific embodiments of the present invention.

Example I 9.75 moles of hydrogen chlorideand 4.90 moles of diallyl ether were placed in a glass reaction vessel in the presence of about 2 per cent of cuprous chloride based on the weight of diallyl ether. The contents of the vessel were maintained at about 30 C. and under approximately atmospheric pressure. After about 2 hours the contents of the reaction vessel were neutralized with aqueous sodium hydroxide and the organic liquid phase was fractionally distilled. 85.4% of the diallyl ether charged was found to have been converted to allyl chloride and 14.6% of the diallyl ether was recovered unreacted.

Example II 12.5 moles of hydrogen chloride and 4.1 moles of diallyl ether were charged into a steel reaction vessel containing about 1% cuprous chloride based on the weight of diallyl ether. The contents of the reaction vessel were maintained for one hour at a temperature of about 30 C. and under a maximum pressure of 150 pounds per square inch (gauge). After separation as in the preceding example, 90 per cent of the diallyl ether was found to have been converted to allyl chloride. Ninety-seven per cent of the hydrogen chloride used was recovered as free acid or in the form of allyl chloride.

Example III Ten moles of hydrogen chloride and two moles of di(methallyl) ether were charged into a reaction vessel containing about 1.5% of cuprous chloride based upon the weight of di(methallyl) ether. The contents of the reaction vessel were maintained at a temperature of about C. to about C. and under a maximum pressure of about 175 pounds per square inch (gauge) for about two hours. Methallyl chloride was recovered by the method employed in the preceding examples, in good yield based upon the di(methallyl) ether consumed.

Example IV One half mole of dicrotyl ether was contacted at substantially atmospheric pressure with about 1.5% by weight of cuprous bromide under an atmosphere of gaseous hydrogen bromide in a reaction vessel connected with a reservoir of hydrogen bromide sufficient to provide at least 4 moles of hydrogen bromide gas per mole of dicrotyl ether. After a reaction period of about 5 hours at about 40 C., the liquid reaction mixture was removed from the reaction vessel, washed with aqueous alkali, and fractionally distilled. Crotyl bromide was recovered in good yield based upon the dicrotyl ether consumed.

Example V Example I was repeated, using hydrogen bromide instead of hydrogen chloride. Allyl bromide was recovered from the reaction mixture in good yield based upon the diallyl ether consumed.

I claim as my invention:

1. A process which comprises (a) mixing a symmetrical bis(2-alkenyl) ether containing an even number of carbon atoms not less than 6 nor greater than 8 with an excess of a hydrogen halide selected'from the class consisting of hydrogen chloride and hydrogen bromide, (b) reacting said ether in liquid phase with said hydrogen halide present in an amount corresponding to a molar ratio of hydrogen halide: bis (2-alkenyl) ether not less than about 4:1 at a temperature within the range of from 15 C. to 40 C. under substantially anhydrous conditions at a superatmospheric pressure between about 30 lbs. per square inch and about 200 lbs. per square inch in the presence of a cuprous halide corresponding to said hydrogen halide as catalyst, and (0) recovering a 2-alkenyl halide from the resulting mixture.

2. A process which consists in reacting diallyl ether in liquid phase with hydrogen chloride present in an amount corresponding to a molar ratio of hydrogen chloridezdiallyl ether not less than about 4:1, at a temperature within the range of from 15 C. to 40 C. at a superatmospheric pressure between about 30 lbs. per square inch and about 200 lbs. per square inch and in the presence of cuprous chloride, and recovering allyl chloride from the resulting mixmm.

3. A process which consists in reacting di- (methallyl) ether in liquid phase with hydrogen chloride present in an amount corresponding to a molar ratio of hydrogen chloridezdi- (methallyl) ether not less than about 4:1, at a temperature within the range of from 15 C. to 40C. at a superatmospheric pressure between about 30 lbs. per square inch and about 200 lbs. per'square inch and in the presence of cuprous chloride, and recovering methallyl chloride from the resulting mixture.

4. A process which consists in reacting dicrotyl ether in liquid phase with hydrogen chloride present in an amount corresponding to a molar ratio of hydrogen chloridezdicrotyl ether not less than about 4:1, at a temperature within the range of from 15 C. to 40 C. at a superatmospheric pressure between about 30 lbs. per square inch and about 200 lbs. per square inch and in the presence of cuprous bromide, and recovering crotyl chloride from the resulting mixture.

5. A process which comprises (a) mixing a symmetrical bis(2-alkenyl) ether containing an even number of carbon atoms not less than 6 nor greater than 8 with an excess of a hydrogen halide selected from the class consisting of hydrogen chloride and hydrogen bromide, (b) reacting said ether in liquid phase with said hydrogen halide present in an amount corresponding to a molar ratio of hydrogen halide: bis- (Z-alkenyl) ethernot less than about 2:1 at a temperature within the range of from 15 C. to 40 C. under substantially anhydrous conditions at a superatmospheric pressure between about 30 lbs. per square inch and about 200 lbs. per square inch in the presence of a cuprous halide corresponding to said hydrogen halide as catalyst, and (c) recovering a 2-alkenyl halide from the resulting mixture.

GEORGE J. CARLSON.

REFERENCES CITED The following references are of record in the file of this (patent:

UNITED STATES PATENTS Number Name Date 2,168,167 Leuchs Aug. 1, 1939 2,176,055 Britton et al Oct. 17, 1939 2,210,564 Andrussow Aug. 6, 1940 OTHER REFERENCES Classification Bulletin of the U. S. Patent Office No. 85, Class 260, Chemistry, Carbon Compounds (1943), pages 6 and 44. 

5. A PROCESS WHICH COMPRISES (A) MIXING A SYMMETRICAL BIS(2-ALKENYL) ETHER CONTAINING AN EVEN NUMBER OF CARBON ATOMS NOT LESS THAN 6 NOR GREATER THAN 8 WITH AN EXCESS OF A HYDROGEN HALIDE SELECTED FROM THE CLASS CONSISTING OF HYDROGEN CHLORIDE AND HYDROGEN BROMIDE, (B) REACTING SAID EITHER IN LIQUID PHASE WITH SAID HYDROGEN HANDLE PRESENT IN AN AMOUNT CORRESPONDING TO A MOLAR RATIO OF HYDROGEN HALIDE: BIS(2-ALKENYL) ETHER NOT LESS THAN ABOUT 2:1 AT A TEMPERATURE WITHIN THE RANGE OF FROM 15*C. TO 40*C. UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS AT A SUPERATMOSPHERIC PRESSURE BETWEEN ABOUT 30 LBS. PER SQUARE INCH AND ABOUT 200 LBS. PER SQUARE INCH IN THE PRESENCE OF A CUPROUS HALIDE CORRESPONDING TO SAID HYDROGEN HALIDE AS CATALYST, AND (C) RECOVERING A 2-ALKENYL HANDLE FROM THE RESULTING MIXTURE. 